1. Technical Field
This disclosure relates to modular surgical implants and more particularly to modular implants for replacement, repair and/or augmentation of hard tissue.
2. Background of Related Art
Surgical implants are commonly used to replace, repair or augment hard tissue in the body of a patient and may be utilized when a body part is mutilated or damaged through trauma or disease. Surgical implants are also used as replacements or augmenters in cosmetic or plastic surgery.
Various materials are known in the art which can be used for making surgical implants. Examples of such materials are chromium-cobalt-molybdenum alloys, stainless steel, titanium alloys, ceramics and various polymers and polymer/ceramic composites. The materials used for surgical implants should be biocompatible, i.e., they must not adversely affect living tissue and the environment created by living tissue must not adversely affect the prosthetic.
In many cases, surgical implants must patch, replace or augment body parts such as bone which are rigid. Consequently, the implants are normally composed, at least in part, of rigid material. Additionally, the implants should approximate the size and shape of the body part being replaced or augmented. Since every patient is unique, a problem which often confronts practitioners is finding an implant with the requisite shape and proper fit, especially in instances where rigid implants are required.
In certain instances, a custom surgical implant is formed by making a mold of the body part of the individual patient and then deriving a custom surgical implant from the mold. A problem associated with this method is that it is time consuming due to the effort required in making the mold and then casting the implant. This also translates into higher costs for the patient. In other methods, a surgical implant is formed to the approximate size and shape of the body part and is subsequently carved or sculpted to fit the needs of the particular patient. The problem associated with achieving precise size and shape is compounded when the surgical implant is composed of rigid material, i.e., once the implant is formed it is time consuming and difficult to make adjustments to its size and shape. Any mistakes made in adjusting the configuration are difficult to correct and may require the fabrication of an entirely new implant.
Standardized preformed rigid implants have also been utilized. However, these standardized implants ordinarily do not account for differences in the bone or tissue structure among patients and may also have to be individually carved to the necessary shape to ensure a proper fit.
Additionally, in some surgical situations, the implants may be required to be inserted to the implant site via a tortuous or curved pathway. Insertion of a rigid implant along such pathway may damage surrounding tissue or may even cause fracture of the implant itself.
Therefore, the need exists for surgical implants, formed of a rigid material, which can accommodate the needs of individual patients without requiring each implant to be separately molded or individually sculpted to the required configuration. Such implants would simplify implantation and thus limit complicated time consuming and expensive surgical procedures. One such implant is disclosed in co-pending U.S. application Ser. No. 08/069,452 which discloses an implant of a plurality of spaced apart segments attached by flexible connecting members which can be bent to re-orient the segments so that the implant approximates the size and shape of the body part being treated.